1. Field of the Invention
The invention relates to an error detection circuit interrupter device that includes a detection circuit for determining whether an error has occurred in an exterior circuit and includes an interrupter device for stopping current flow to the exterior circuit when an error has been detected. More particularly, the invention relates to a ground fault circuit interrupter device (GFCI) that includes a detection circuit for determining whether a ground fault has occurred in an exterior circuit and includes an interrupter device for stopping current flow to the exterior circuit when a ground fault has been detected.
2. Description of the Related Art
Fault or error detection devices are well known in the art to provide additional safety for electrical components. A specific type of fault or error detection device is know as a GFCI device. In operation, a GFCI type device supplies electricity to an exterior circuit and opens an outlet circuit when a ground fault occurs in the exterior circuit, i.e., when a portion of a circuit that is plugged into the outlet becomes grounded. For example, if a hair dryer is negligently dropped into a bathtub, electricity may flow from the hair dryer circuit to ground through the bathtub water. A person might be part of the current path to ground. An electrical outlet provided with a GFCI device will detect such a ground fault and, almost instantaneously, open the outlet circuit to prevent current from flowing from the hair dryer circuit to ground. Although the GFCI device is described above as being associated with an outlet, the typical GFCI device can be associated with other different types of electrical junctures.
Conventional GFCI devices include a detection circuit that compares the current leaving the outlet circuit to the current returning to the outlet circuit. When there is a pre-set differential between the leaving and returning outlet currents, the GFCI opens the outlet circuit and indicates that a ground fault has occurred. The detection circuit can be constructed in a number of different ways, including providing a differential transformer for sensing the imbalance in the current flow. In addition, there are many different structures that have conventionally been used to open the circuit once the ground fault has been detected. For example, some conventional GFCI devices use a trip coil to open the outlet circuit. A test and reset button are also typically provided on the GFCI device for testing whether the device is functioning properly and for resetting the device after testing or after the device has been tripped. Conventional GFCI devices are often complicated structures that require sophisticated manufacturing processes to ensure that they work properly and safely. Several other drawbacks exist in the conventional GFCI devices, including high manufacturing cost, poor reliability, poor endurance, potential safety concerns due to excessive heat generation and/or poor reliability, and general aesthetic and ergonomic drawbacks.